Most automobiles have two fuse panels. The fuse panel in the engine compartment typically contains the fuses for protection of the electrical circuits associated with vehicle functions such as cooling fans, anti-lock brakes, and engine control units. An interior fuse panel, usually located under the dash on the driver's side, protects electrical circuits associated with electrical devices inside the passenger compartment. Different fuse designs have different rating ranges. For example, AGU fuses (the glass cylinder type) are commercially available with ratings between 5 and 60 amps. MAXI fuses (blade type) are commercially available with ratings between 40 and 100 amps. The more expensive ANL (automatic noise limiting) fuses (wafer type) are commercially available with ratings between 60 and 300 amps, and are generally provided as power wire inline battery fuses. For even larger loads, circuit breakers may be required.
Improvements in electronics have also increased the development and availability of high technology accessories for vehicles and recreational vehicles, such as CD players, DVD players, televisions, computers, high powered amplifiers, various stereo system components, and other appliances configured to operate at low voltages. The number of custom options available far exceeds the availability, capacity, and design of the original vehicle equipment or the factory supplied electric circuits.
Frequently, the load requirement of a vehicle accessory exceeds the highest rated fuse that can fit in a factory supplied fuse panel. For example, many stereo amplifiers are rated at 2,000 or even 3,000 watts. 150 amp fuses are required for such an accessory. As a result, a separate fuse box, block or panel must generally be purchased for the custom accessory, which block must accommodate the larger amp fuses.
The available space for such fuse blocks is limited, not to mention the further disadvantage that the custom electrical devices may also have significantly different load requirements, meaning different—higher or lower—current circuits with corresponding fuse ratings, may also be required, necessitating the purchase of more than one additional fuse block or panel. As a result of these custom design criteria, two or three different power distribution blocks may be required to accommodate different fuse designs, as well as the different sizes of AWG gage input wires.
The large custom automobile market has also created a special demand for additional power distribution and high current load capable circuits. Multiple amplifiers in a custom audio system require maximum power for peak performance. Safely moving power from a vehicle battery to the amplifiers requires high performance power distribution and specific fuse capability. These applications require solutions that not only satisfy the electrical system functionality requirements and protect the expensive accessories, but the solutions are desired to be cosmetically enhancing. For example, the custom automobile industry may use fancy or stylish fuses (gold plated), and highly decorative architecture for the fuse panel.